diff --git a/groth16/example/example.nim b/groth16/example/example.nim
index fd610f2..a431a86 100644
--- a/groth16/example/example.nim
+++ b/groth16/example/example.nim
@@ -4,15 +4,15 @@ import groth16/files/export_json
 
 #-------------------------------------------------------------------------------
 
-proc exampleProveAndVerify() = 
+proc exampleProveAndVerify() =
   let zkey_fname : string = "./build/product.zkey"
   let wtns_fname : string = "./build/product.wtns"
-  let proof = testProveAndVerify( zkey_fname, wtns_fname)
-  
+  let (_, proof) = testProveAndVerify( zkey_fname, wtns_fname)
+
   exportPublicIO( "./build/nim_public.json" , proof )
   exportProof(    "./build/nim_proof.json"  , proof )
 
 #-------------------------------------------------------------------------------
 
 when isMainModule:
-  exampleProveAndVerify()
\ No newline at end of file
+  exampleProveAndVerify()
diff --git a/groth16/example/product.circom b/groth16/example/product.circom
index b1bb644..a0b5283 100644
--- a/groth16/example/product.circom
+++ b/groth16/example/product.circom
@@ -30,7 +30,7 @@ template Main(n) {
   component prod = Product(n);
   inp ==> prod.inp;
   out <== prod.out + plus;
-  log("out =",out);
+  // log("out =",out);
 
   out === 2023;
 }
diff --git a/groth16/files/export_json.nim b/groth16/files/export_json.nim
index cc1c0c6..5f6fa15 100644
--- a/groth16/files/export_json.nim
+++ b/groth16/files/export_json.nim
@@ -3,19 +3,23 @@
 # export proof and public input in `circom`-compatible JSON files
 #
 
-import pkg/constantine/math/arithmetic   except Fp, Fr
-#import constantine/math/io/io_fields except Fp, Fr
+import pkg/constantine/math/arithmetic
+import pkg/constantine/math/io/io_fields
+# import pkg/constantine/math/config/curves
+
+import pkg/constantine/named/properties_fields
+import pkg/constantine/math/extension_fields/towers
 
 import groth16/bn128
 from groth16/prover import Proof
 
 #-------------------------------------------------------------------------------
 
-func toQuotedDecimalFp(x: Fp): string =
+func toQuotedDecimalFp(x: Fp[BN254Snarks]): string =
   let s : string = toDecimalFp(x)
   return ("\"" & s & "\"")
 
-func toQuotedDecimalFr(x: Fr): string =
+func toQuotedDecimalFr(x: Fr[BN254Snarks]): string =
   let s : string = toDecimalFr(x)
   return ("\"" & s & "\"")
 
@@ -24,7 +28,7 @@ func toQuotedDecimalFr(x: Fr): string =
 # exports the public input/output into as a JSON file
 proc exportPublicIO*( fpath: string, prf: Proof ) =
 
-  # debugPrintFrSeq("public IO",prf.publicIO)
+  debugPrintFrSeq("public IO",prf.publicIO)
 
   let n : int = prf.publicIO.len
   assert( n > 0  )